Detection of blaCTX-M-15 in an integrative and conjugative element in four extensively drug-resistant Haemophilus parainfluenzae strains causing urethritis

Haemophilus parainfluenzae is a commensal organism with rising numbers of multidrug-resistant (MDR) strains. This pathogen is of increasing clinical relevance in urogenital infection. The aim of this work was to identify and characterise the molecular mechanisms of resistance associated with four cephalosporin-resistant H. parainfluenzae strains collected from patients with urethritis. Antimicrobial resistance was determined by microdilution following European Committee on Antimicrobial Susceptibility Testing criteria. Strains were then analysed by whole-genome sequencing to determine clonal relationship and the molecular basis of antimicrobial resistance. Finally, a phylogenetic analysis was performed on all urogenital MDR strains of H. parainfluenzae previously isolated in our hospital. All strains were resistant to β-lactams, macrolides, tetracycline, fluoroquinolones, chloramphenicol, cotrimoxazole, and aminoglycosides. The resistance profile was compatible with the presence of an extended-spectrum β-lactamase (ESBL). Whole-genome sequencing detected blaCTX-M-15 that conferred high minimum inhibitory concentrations to cephalosporins in two novel integrative and conjugative elements (ICEHpaHUB6 and ICEHpaHUB7) that also harboured a blaTEM-1 β-lactamase. This study shows a novel blaCTX-M-15 ESBL carried in an integrative conjugative element in four extensively drug-resistant H. parainfluenzae strains. This resistance determinant could be transmitted to other sexually transmitted pathogens and this is a cause for concern.

Genomic and phylogenetic analysis of a multidrug-resistant Klebsiella pneumoniae ST15 strain co-carrying blaOXA-232 and blaCTX-M-15 recovered from a gallbladder infection in China

OBJECTIVES

The occurrence of OXA-232-producing carbapenem-resistant Klebsiella pneumoniae (CRKP) has been increasing in China during the last five years. The bla_OXA-232-carrying CRKP strain's clonal propagation can readily lead to nosocomial epidemics. Here, we report the genome sequence of OXA-232 and CTX-M-15 co-producing K. pneumoniae strain isolated from a gallbladder infection in China.

METHODS

The genome sequence of K. pneumoniae S105 was determined using the Illumina NovaSeq 6000 platform. Antimicrobial resistance genes (ARGs), multilocus sequence typing (MLST) and plasmid replicons were identified using the BacWGSTdb server. The phylogenetic relationship between S105 and other K. pneumoniae strains was analysed using the core genome multilocus sequence typing (cgMLST) strategy.

RESULTS

The genomic sequence of K. pneumoniae S105 is made up of 111 contigs with a total length of 5,748,752 bp. According to the Pasteur MLST scheme, S105 belongs to sequence type (ST) 15. Fifteen ARGs were discovered in the genome, including the beta-lactam resistance genes bla_OXA-232 and bla_CTX-M-15. The bla_OXA-232 gene was located in a ColKP3 plasmid. KL112 was anticipated to be the capsule and lipopolysaccharide serotype. A total of 73 phylogenetically related strains were found from 19 nations across four continents; 22 of them were from China, with 21 strains harboring the bla_OXA-232 gene, and the majority of them diverged by just 6-37 cgMLST alleles.

CONCLUSIONS

In summary, we reported the genomic sequencing of a K. pneumoniae ST15 clinical strain that co-carrying the bla_OXA-232 and bla_CTX-M-15 genes. The clonal dissemination of OXA-232-producing K. pneumoniae ST15 strains in China needs our attention.

Genomic and phylogenetic analysis of a community-acquired extended-spectrum β-lactamase-producing Escherichia coli ST429 strain recovered from a urinary tract infection

OBJECTIVES

Escherichia coli is one of the most prevalent bacterial pathogens causing urinary tract infections (UTIs). The increasing dissemination of extended-spectrum β-lactamase (ESBL)-producing E. coli in the community renders clinical treatment difficult. Here we report the complete genome sequence of a bla_CTX-M-15-carrying E. coli strain (EC28) isolated from a urine sample of a female outpatient with UTI.

METHODS

The whole genome sequence of E. coli strain EC28 was determined using both a MinION™ sequencer and an Illumina NovaSeq 6000 system. De novo hybrid assembly of the short Illumina reads and long MinION reads was performed using Unicycler. Multilocus sequence typing (MLST), antimicrobial resistance genes (ARGs), plasmid replicons and phylogenetic relationship were analysed using the BacWGSTdb database.

RESULTS

The genome sequence of E. coli strain EC28 consists of six contigs comprising 5260 133 bp, including one chromosome and five plasmids. According to MLST analysis, EC28 belongs to ST429. Six ARGs were identified, including bla_CTX-M-15 located on a 63,295-bp IncI2-type plasmid. Twenty-three phylogenetically related E. coli ST429 strains were identified in the NCBI GenBank database, none recovered from China. The closest relative was an isolate recovered from Japan in 2009 that differed by 146 cgMLST loci.

CONCLUSION

Here we report the first complete genome sequence of an ESBL-producing E. coli ST429 strain isolated from the community in China. The genome sequence of EC28 can be used as a reference sequence for comparative analysis, including acquisition and mobilisation of bla_CTX-M genes in community-acquired E. coli strains.

First Indian report on B4/H24RxC ST410 multidrug-resistant Escherichia coli from bloodstream infection harbouring blaOXA-181 and blaCTX-M-15

OBJECTIVES

Escherichia coli is regarded as one of the most commonly isolated Gram-negative pathogens from bloodstream infections. Increasing antimicrobial resistance (AMR) among E. coli is a threat to disease management as well as further dissemination of AMR genes to other clinically important pathogens. Here we report the genome of a multidrug-resistant (MDR) E. coli (BA22372) from a bloodstream infection belonging to ST410 B4/H24RxC subtype from India.

METHODS

Genomic DNA of E. coli BA22372 was sequenced using Ion Torrent™ PGM™ and MinION™ sequencing. Hybrid genome assembly was performed using short and long reads from both methods to achieve accurate and complete genome data.

RESULTS

Here we report the genome of MDR E. coli BA22372 harbouring bla_OXA-181 and bla_CTX-M-15 in two individual plasmids, namely pOXA181_22372 (IncX3) and pCTX-M-15_22372 (IncF). The pCTX-M-15 plasmid is well known to co-harbour bla_NDM-5, which was not seen in the studied isolate here.

CONCLUSION

To the best of our knowledge, this is the first report of B4/H24RxC MDR E. coli from India co-harbouring bla_CTX-M-15 and bla_OXA-181 along with other AMR genes. Information from this genome data revealed the possession of AMR genes in two individual plasmids and their potential for rapid dissemination. This isolate is of high health concern as it harbours a plasmid with replicatory mechanisms capable of acquiring bla_NDM-5, which is a great threat for rapid dissemination of AMR. This study enhances our understanding of the AMR mechanisms among different clones of E. coli.

Complete and assembled genome sequence of an NDM-9- and CTX-M-15-producing Klebsiella pneumoniae ST147 wastewater isolate from Switzerland

OBJECTIVES

Carbapenem-resistant Klebsiella pneumoniae have emerged worldwide and represent a major threat to human health. Here we report the genome sequence of K. pneumoniae 002SK2, an NDM-9- and CTX-M-15-producing strain isolated from wastewater in Switzerland and belonging to the international high-risk clone sequence type 147 (ST147).

METHODS

Whole-genome sequencing of K. pneumoniae 002SK2 was performed using Pacific Biosciences (PacBio) single-molecule, real-time (SMRT) technology RS2 reads (C4/P6 chemistry). De novo assembly was performed using Canu assembler, and sequences were annotated using the NCBI Prokaryotic Genome Annotation Pipeline (PGAP).

RESULTS

The genome of K. pneumoniae 002SK2 consists of a 5.4-Mbp chromosome containing bla_SHV-11 and fosA6, a 159-kb IncFIB(K) plasmid carrying the heavy metal resistance genes ars and sil, and a 77-kb IncR plasmid containing bla_CTX-M-15, bla_NDM-9, bla_OXA-9 and bla_TEM-1.

CONCLUSIONS

Multidrug-resistant K. pneumoniae harbouring bla_NDM-9 and bla_CTX-M-15 are spreading into the environment, most probably via wastewater from clinical settings.

Draft genome sequences of two fluoroquinolone-resistant CTX-M-15-producing Escherichia coli ST90 (ST23 complex) isolated from a calf and a dairy cow in South America

OBJECTIVES

Farm animals have been recognised as important carriers and reservoirs of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli. The aim of this study was to report the draft genome sequences of two multidrug-resistant (MDR) CTX-M-15-producing E. coli strains (47VL and 13B) isolated from different bovine hosts (a calf and a dairy cow), housed separately in a commercial dairy farm in Brazil.

METHODS

Total genomic DNA of the E. coli isolates was sequenced using an Illumina MiSeq paired-end 300-bp sequencing platform. Sequence reads were de novo assembled using the A5-miseq pipeline and polishing assembly in Geneious v.R9. The NCBI Prokaryotic Genome Annotation Pipeline v.3.2 was used for genome annotation, whereas whole-genome sequences were analysed using bioinformatic tools from the Center of Genomic Epidemiology and EnteroBase.

RESULTS

E. coli 47VL generated a total of 3238770 and E. coli 13B a total of 1422808 paired-end reads of ca. 190× and ca. 80×, respectively. The resistome revealed that both isolates carried resistance genes to aminoglycosides, β-lactams, macrolides, sulphonamides, trimethoprim and tetracycline. Comparative analyses revealed clonal relatedness. In fact, both isolates belonged to sequence type ST90 (clonal complex CC23) and phylogroup AxB1.

CONCLUSION

To our knowledge, these are the first draft genome sequences of CTX-M-15-producing E. coli ST90 isolated from bovines in South America. These data can be used to elucidate genetic features that contribute to colonisation and adaptation of CTX-M-15-producing E. coli in dairy cattle.

Draft genome sequence of Enterobacter cloacae ST520 harbouring blaKPC-2, blaCTX-M-15 and blaOXA-17 isolated from coastal waters of the South Atlantic Ocean

OBJECTIVES

Aquatic environments have contributed to the dissemination of multidrug-resistant (MDR) bacteria, representing a risk for humans and animals. The aim of this study was to report the first draft genome sequence of a MDR Enterobacter cloacae strain recovered from seawater in a public beach in Brazil.

METHODS

The genome was sequenced on an Illumina MiSeq platform. De novo genome assembly was performed using SPAdes 3.10.1 and the whole genome sequence was analysed using bioinformatics tools from the Center of Genomic Epidemiology.

RESULTS

This draft genome resulted in 5 228 857bp with 5331 protein-coding sequences, revealing the presence of bla_KPC-2, bla_CTX-M-15 and bla_OXA-17 genes, responsible for resistance to all β-lactam antibiotics. In addition, the strain was assigned to sequenced type 520 (ST520).

CONCLUSION

These data provide useful information for comparative genomic analysis regarding the dissemination of antibiotic resistance genes.

Draft genome sequence of a CTX-M-15-producing Klebsiella pneumoniae sequence type 340 (clonal complex 258) isolate from a food-producing animal

Klebsiella pneumoniae carrying bla_CTX-M-15 have been widely disseminated in hospital settings. In this regard, most clinically important strains belong to clonal complex 28 (CC258), which includes sequence type 340 (ST340). In this study, we present the draft genome sequence of a CTX-M-15-producing ST340 K. pneumoniae strain isolated from a food-producing animal in Brazil.

Dissemination of the multidrug-resistant extended-spectrum β-lactamase-producing Escherichia coli O25b-ST131 clone and the role of house crow (Corvus splendens) foraging on hospital waste in Bangladesh

Two hundred and thirty-eight faecal samples from crows foraging on hospital wastes were analysed for extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae. ESBL-producing crow isolates were characterized and compared with 31 patient isolates. Among the crows, 59% carried ESBL producers. These included Escherichia coli, Klebsiella pneumoniae, Raoultella terrigena and Enterobacter cloacae harbouring the genes for CTX-M-1, CTX-M-15, CTX-M-55, CTX-M-79, and CTX-M-14. Human isolates carried only the CTX-M-15 gene. Two-thirds of crow E. coli isolates and all human E. coli isolates were multidrug resistant. Crows and patients shared E. coli sequence types, including the epidemic E. coli O25b-ST131 clone. The scavenging behaviour of crows at poorly managed hospital waste dumps made them potential reservoirs of antibiotic resistance, including ESBLs.

Different IncI1 plasmids from Escherichia coli carry ISEcp1-blaCTX-M-15 associated with different Tn2-derived elements

The bla(CTX-M-15) gene, encoding the globally dominant CTX-M-15 extended-spectrum β-lactamase, has generally been found in a 2.971-kb ISEcp1-bla(CTX-M-15)-orf477Δ transposition unit, with ISEcp1 providing a promoter. In available IncF plasmid sequences from Escherichia coli, this transposition unit interrupts a truncated copy of transposon Tn2 that lies within larger multiresistance regions. In E. coli, bla(CTX-M-15) is also commonly associated with IncI1 plasmids and here three such plasmids from E. coli clinical isolates from western Sydney 2006-2007 have been sequenced. The plasmid backbones are organised similarly to those of other IncI1 plasmids, but have insertions and/or deletions and sequence differences. Each plasmid also has a different insertion carrying bla(CTX-M-15). pJIE113 (IncI1 sequence type ST31) is almost identical to plasmids isolated from the 2011 E. coli O104:H4 outbreak in Europe, where the typical bla(CTX-M-15) transposition unit interrupts a complete Tn2 inserted directly in the plasmid backbone. In the novel plasmid pJIE139 (ST88), ISEcp1-blaC(TX-M-15)-orf477Δ lies within a Tn2/3 hybrid transposon. Homologous recombination could explain movement of ISEcp1-bla(CTX-M-15)-orf477Δ between copies of Tn2 on IncF and IncI1 plasmids and generation of the Tn2/3 hybrid. pJIE174 (ST37) is almost identical to pESBL-12 from the Netherlands and in these plasmids bla(CTX-M-15) is flanked by two copies of IS26 that truncate the transposition unit within a larger region bounded by the ends of Tn2. bla(CTX-M-15) and the associated ISEcp1-derived promoter may be able to move from this structure by the actions of IS26, independently of both ISEcp1 and Tn2.

Distribution and molecular characterization of genes encoding CTX-M and AmpC β-lactamases in Escherichia coli isolated from an Indian urban aquatic environment

Aquatic environments harboring antibiotic resistant Escherichia coli constitute an important public health concern. Thus, it is important to characterize the resistance genetic elements of waterborne E. coli. It is also important to identify the predominant clonal groups/phylogroups represented by resistant strains to understand the epidemiology of antibiotic resistant E. coli in natural environments, and to identify the role of well-established genotypes in the spread of resistance in a particular geographical area through natural environments. In the present investigation, E. coli strains (n=126) isolated from various points along the river Yamuna traversing through the National Capital Territory of Delhi (India) were grouped phylogenetically. A collection of 61 strains representing all phylogroups was investigated for extended-spectrum β-lactamase (ESBL) and AmpC production. blaTEM, blaSHV and blaCTX-M genes were detected and analyzed, promoter/attenuator mutations associated with chromosomally-mediated AmpC overexpression were identified, and plasmid-mediated ampC was determined. blaTEM was the most widespread (100%) gene followed by bla(CTX-M) (16%), and plasmid-mediated ampC (3%). bla(CTX-M-15) and bla(CMY-42) were identified as the genes encoding CTX-M type ESBL and CIT type AmpC β-lactamases, respectively. CTX-M-15 ESBL phenotype was most common in phylogroup D (50%), followed by phylogroups B1 (30%), and A (20%). E. coli that produce plasmid-mediated AmpC were rare and present only in phylogroup D. Presence of multi β-lactam resistance, bla(CTX-M-15) and bla(CMY-42) in waterborne E. coli belonging to virulence-associated phylogroup D highlights the need for routine surveillance of resistance determinants in aquatic environments. This is also the first report for the presence of bla(CMY-42) in waterborne E. coli.

Fecal carriage of multi-drug resistant and extended spectrum β-lactamases producing E. coli in household pigeons, Bangladesh

Antibiotic resistance and ESBL constitute a risk to human and animal health. Birds residing close to humans could mirror the spectrum of human associated antibiotic resistance. Household pigeons were screened in Bangladesh to shed light on human associated, as well as, environmental antibiotic resistance. Escherichia coli from pigeons (n=150) were tested against 11 antibiotics. 89% E. coli isolates were resistant to one or more critically important human antibiotics like ampicillin, cefadroxil, mecillinam, ciprofloxacin, gentamicin and tigecycline. No carbapenamase-producers were detected and the lower ESBL prevalence (5%) in pigeons. ESBL-producing E. coli isolates had blaCTX-M-15 genes. Pigeons shared some bacterial clones and had bird associated sequence types like E. coli ST1408. Fecal carriage of bacteria resistance of critically important human antibiotics, together with examples of shared genotypes among pigeons, indicate the human-birds and bird to bird transmissions are important in the epidemiology of antibiotic resistance.

Detection of chromosomal blaCTX-M-15 in Escherichia coli O25b-B2-ST131 isolates from the Kinki region of Japan

Escherichia coli O25b-B2-ST131 isolates harbouring bla(CTX-M-15) are distributed worldwide. The bla(CTX-M-15) transposition unit has often been found on plasmids and the genetic contexts have been examined; however, less is known about the frequency and contexts of the bla(CTX-M-15) transposition unit on the chromosome. This study was performed to determine the chromosomal location of the bla(CTX-M-15) transposition unit and to analyse the molecular structure of the region surrounding the bla(CTX-M-15) transposition unit in E. coli O25b-B2-ST131 isolates. Twenty-two E. coli O25b-B2-ST131 strains harbouring bla(CTX-M-15) that had been isolated from university hospital patients and nursing home residents in the Kinki region of Japan were examined. Inverse PCR (iPCR) targeting bla(CTX-M-15) was performed to classify the molecular structure of the region surrounding the bla(CTX-M-15) transposition unit. The isolates were classified into nine types (types A-I) considering the iPCR results; type A was the most prevalent type (13/22 isolates). Sequences of the iPCR-amplified DNA fragments showed that the bla(CTX-M-15) transposition unit consisted of ISEcp1, bla(CTX-M-15) and orf477Δ. A homology search of the obtained sequences showed that the bla(CTX-M-15) transposition unit was inserted into different chromosomal regions in eight of the nine classified types. Although 21 of the 22 E. coli isolates possessed chromosomally located bla(CTX-M-15) transposition units, clonal spread was not evident on pulsed-field gel electrophoresis (PFGE) analysis. Taken together, these data indicate that certain E. coli O25b-B2-ST131 strains harbouring chromosomal bla(CTX-M-15) have emerged and spread in the Kinki region of Japan.